/Engine/Source/Runtime/Slate/Public/Widgets/Input/SMultiLineEditableTextBox.h
Get the runs currently that are current selected, some of which may be only partially selected
[TArray](API\Runtime\Core\Containers\TArray)< [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< const [IRun](API\Runtime\Slate\Framework\Text\IRun) > > GetSelectedRuns() const